BAGHDAD, Iraq — Kidnappers holding four Westerners made no contact with Iraqi authorities on Saturday, the day they had set as a deadline to kill the Christian peace activists unless U.S. and Iraqi authorities release all prisoners, the interior ministry said.

The ministry had received no information about the four Christian activists by late morning Saturday, a spokesman said.

The previously unknown Swords of Righteousness Brigade set Saturday as a deadline for killing Norman Kember, 74, of London, Tom Fox, 54, of Clear Brook, Va., and Canadians James Loney, 41, and Harmeet Singh Sooden, 32.

The group seized the four members of the Christian Peacemaker Teams two weeks ago. It first set a Thursday deadline but then extended it until Saturday, without setting a precise hour.

On Friday, Sunni Arab clerics used their main weekly religious service to plead for the hostages' lives because of their humanitarian work and condemnation of the U.S.-led war in Iraq.

"We ask those who have authority and power to do their best to release the four European people who work in Christian peace organization," cleric Ahmed Hassan Taha told worshippers in Baghdad's Sunni stronghold Azamiyah. "In fact those activists were the first who condemned the war on Iraq."

Residents gathered outside the mosque held aloft banners demanding their release.

"The people of Azamiyah will not forget the honest positions of the peacemakers," read one. Another said "we demand the release of the abducted peacemakers."

A French aid worker and a German citizen are also being held by kidnappers. There was no word early Saturday on the fate of an American hostage, Ronald Allen Schulz, after an Internet statement in the name of the Islamic Army in Iraq claimed his abductors had killed him.

Elsewhere in Iraq, a roadside bomb targeting a U.S. military patrol in the northern city of Mosul killed two Iraqi civilians and injured one Saturday.

Gunmen also killed Ali Omeir, an official at a local non-governmental aid group, in northern Mosul's Sukar neighborhood as he was heading for work.

A suicide car bomb attack on a U.S. army unit in western Baghdad on Friday killed one soldier and wounded 11 others, as well as wounding an Iraqi civilian, the U.S. military said Saturday.

American troops detained a high-ranking member of al-Qaida in Iraq after he was turned in Friday by residents of Ramadi, the U.S. military said.